The overall objective is to study the structure and function of transfer RNA and its role in cellular processes. At present we are studying the m5U methyltransferase and the uridine-5-oxyacetic acid methyltransferase, both from E. coli. We have developed a very simple and rapid purification procedure capable of yielding pure m5U methyltransferase in high yield. This procedure involves the use of just two chromatographic steps and we believe that it is one of the simplest and most efficient purification schemes for a methyltransferase yet developed. At present we are studying how general this purification scheme is for methyltransferases by attempting to purify the uridine-5-oxyacetic acid methyltransferase by this procedure. We also intend to characterize these enzymes in some detail, including their molecular weights, subunit structures, kinetic parameters and substrate specificities.